5!

What Does 5! Mean?

Definition of "5!"

In a text or online chat, 5! means "Laugh Out Loud" (LOL). It is a super-nerdy mathematical way of expressing amusement (or not!)

LOL for Geeks!

In mathematics, 5! normally means "five factorial," i.e, 5 × 4 × 3 × 2 × 1 = 120. It is used as a nerdy way of saying LOL, because LOL can be written in leetspeak as "101." If you read 101 as a binary number, it equals decimal 5. Adding the exclamation mark turns 5 into 5! (five factorial), which equals 120. To summarize:

LOL → 101
101 (binary) → 5
5! → 120
120 → LOL

Factorial Laughter

LOL is too common for geeks.

Summary of Key Points

5!
Definition:	Laugh Out Loud
Type:	Abbreviation
Guessability:	5: Extremely difficult to guess
Typical Users:	Adults

An Academic Look at 5!

5! is a geeky mathematical pun or an inside joke involving leetspeak and factorial notation. It could be included under a very broad definition of a numeronym, but is probably better described as a mathematical joke, symbolic slang, or nerd humor.

A numeronym is a word where numbers replace part of the word based on the number of omitted letters. Examples include:

b4 = "before" → the number 4 sounds like "fore".
i18n = "internationalization" → the number 18 indicates the number of letters between i and n.
l8r = "later" → the number 8 sounds like "ate".